[kiro-cli] `/editor` command hangs in TUI mode (works in `--classic` mode)

[boday]

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• I have searched for duplicate or closed issues

Operating System

macOS 26.1 (Sequoia), Apple M1 Pro

Kiro Version

1.29.3 (kiro-cli)

Bug Description

The /editor slash command hangs indefinitely when running kiro-cli in the new TUI mode (default). The terminal becomes unresponsive after invoking /editor, requiring a force kill (Ctrl+C or closing the terminal).

The same /editor command works correctly in --classic mode (kiro-cli --classic).

Environment:

• EDITOR=nano (GNU nano 8.7.1)
• TERM=xterm-256color
• TERM_PROGRAM=iTerm.app
• LANG=zh_TW.UTF-8

Suspected cause: The TUI mode may not properly release stdin/stdout control to the external editor process (nano). This could be related to the Kitty protocol sequence handling that was partially fixed in v1.29.2 ("Fixed Kitty protocol sequence leakage by draining stdin on exit") and v1.29.3 ("Fixed tmux pane title showing 'twinki:c' and APC sequence corruption"). The TUI's terminal sequence management may interfere with nano's ability to take over the terminal.

A similar issue was reported in #3463 (v0.4.0, "Terminal loop when opening terminal editors like nano or git diff"), which was closed without resolution.

Steps to Reproduce

1. Ensure EDITOR=nano is set in your shell environment
2. Launch kiro-cli in TUI mode (default): kiro-cli chat
3. Type /editor and press Enter
4. The terminal hangs — nano does not open, no editor UI appears, input is frozen

Workaround that works:

1. Launch kiro-cli in classic mode: kiro-cli --classic
2. Type /editor and press Enter
3. nano opens correctly, content can be edited and submitted

Expected Behavior

When /editor is invoked in TUI mode, kiro-cli should:

1. Properly suspend the TUI and release terminal control (stdin/stdout)
2. Launch the configured $EDITOR (nano) with a temporary .md file
3. Wait for the editor to close
4. Read the content and send it as a prompt
5. Restore the TUI interface

This is the behavior observed in --classic mode, which works correctly.

Conversation ID

No response

Additional Context

• v1.29.2 changelog mentions: "Fixed Kitty protocol sequence leakage by draining stdin on exit" — suggests TUI stdin handling is a known area of concern
• v1.29.3 changelog mentions: "Fixed tmux pane title showing 'twinki:c' and APC sequence corruption" — terminal escape sequence issues in TUI
• Previous related issue: Terminal loop #3463 (v0.4.0, macOS, "Kiro stays in the loop when it opens terminal editors like nano or git diff")
• EDITOR="code --wait" (VS Code) may work as a workaround since it doesn't need terminal control, but terminal-based editors (nano, vim) are expected to work

[github-actions]

🤖 Potential Duplicate Detected

This issue appears to be similar to:

• #6238: Regression in 1.27.0: shell tool keeps stdin open, causing kubectl exec --stdin=true to hang (85% similar)
• #5849: Editor opens to edit TAG_EDITMSG when checkpointing is enabled (85% similar)
• #5481: Subagents result in corrupted terminal output when running in tmux (85% similar)
• #4981: Kiro changes title of the terminal making it hard to know which terminal tab is doing what (85% similar)

What happens next?

• ⏰ This issue will be automatically closed in 3 days
• 🏷️ If this is not a duplicate, you can prevent automatic closure by adding a comment or reacting with 👎 to this message.
• 💬 Comment on the original issue if you have additional information

Why is this marked as duplicate?
Both issues involve stdin/stdout control problems in kiro-cli causing commands to hang. The new issue describes '/editor' hanging due to TUI not releasing terminal control, while #6238 describes shell tool keeping stdin open causing kubectl exec to hang. Both are related to improper stdin handling in the CLI.

[github-actions]

This issue has been automatically closed as it appears to be a duplicate of #6238.

If you believe this is incorrect, please comment on this issue and a maintainer will review it.